Construction of stable Mo x S y /CeO 2 heterostructures for the electrocatalytic hydrogen evolution reaction.

The unique structures of polynuclear Mo x S y clusters make it possible to maximize the number of their active sites and for them to be good candidates for HER catalysts. An appropriate support is highly necessary not only to avoid the desorption of Mo x S y clusters in a working environment, but also to improve their HER activity. Our work here shows that the CeO 2 support could provide strong support for interaction with various Mo x S y clusters and the formed Mo x S y /CeO 2 hetero-structures also have modest Δ G H* for the HER. The electronic features of Mo x S y clusters are regulated by the CeO 2 support, which leads to charge redistribution on edge atoms and plays a key role in H adsorption. Our studies provide instructive predictions on efficient candidates of molybdenum-sulfur based catalysts for the HER.